MM Docket No. 95-17
Amendment of Parts 73 and 74 of the Commission's Rules to More RM-8109 Effectively Protect Radio Astronomy Activity on Channel 37
Adopted: January 27, 1995; Released: February 21, 1995
Comment Date: March 31, 1995
Reply Comment Date: April 21, 1995
By the Commission:
3. To prevent such actions in the future, the National Academy of Sciences' Committee on Radio Frequencies (CORF) petitioned the Commission to amend the rules to include the locations of thirteen radio astronomy sites that currently or will make use of Channel 37, to adopt an 87.7 kilometer (54.5 mile) separation requirement applicable to adjacent channel television stations and to delete Channel 38 at Hilo, Hawaii, from the TV Table of Allotments.(n4)
5. While we do not agree with CORF's argument that our
past decisions entitle radio astronomy use of Channel 37
to site protection, we nevertheless believe that CORF's
proposal merits consideration. We wish to examine whether
some additional protection can be afforded to radio astronomy
sites without significant adverse impact on broadcast services.
We recognize that the sensitivity of radio astronomy equipment
today is undoubtedly much greater than it was in 1963.
Obtaining full benefit from radio astronomy studies may
be facilitated by new precautions intended to limit the
generation of man-made emissions on Channel 37 in the vicinity
of the designated radio astronomy sites. We also note
that the identified radio astronomy locations are mostly
in rural areas. We seek comment on whether TV spectrum
is scarce in any of these areas, either for the existing
TV service or considering the new advanced TV service that
we are proposing in MM Docket No. 87-268.
6. We also request comments on an alternative approach
which is functionally equivalent to the one advocated by
CORF but which is more flexible than a fixed distance separation
requirement and thus less burdensome to broadcasters.
As set forth in Appendix A, we propose to set a limit on
the field strength that a TV station on Channel 36 or 38
could produce at the coordinates of radio astronomy sites
designated by CORF. This alternative would not include
a distance separation requirement. Basing the proposed
protection on field strength will permit stations to be
located closer to the radio astronomy sites than the fixed
distance separation would allow, if the signal radiated
toward the radio astronomy site is suppressed by an appropriate
7. In accordance with Section 73.614 of our rules, a full
service UHF TV station can have a peak visual effective
radiated power (ERP) of 5 megawatts (MW) at an antenna
height above average terrain (HAAT) of 610 meters (2,000
feet). These facilities would deliver a field strength
of approximately 72 dBu at 87.7 kilometers.(n5) However, we
believe that CORF may not have intended to imply that a
72 dBu field strength restriction would provide adequate
protection. A lower field strength value is more consistent
with the power and antenna height at which UHF-TV stations
typically operate. Rather than using maximum allowable
facilities, a more typical UHF station has an ERP between
1 and 5 MW and an antenna HAAT in the vicinity of 350 meters
(1150 feet). These facilities produce a field strength
of 57 to 64 dBu at 87.7 kilometers. We propose to use
64 dBu as the limit on the field strength that a Channel
36 or 38 TV station is permitted to produce at a radio
Another concern leads us to propose the 64 dBu value
in lieu of 72 dBu. The frequency band that might receive
interference is actually in the adjacent Channel 37. An
applicant for a TV station requesting use of a directional
antenna specifies the radiation pattern it will employ
for its on-channel performance; however, a directional
antenna is frequency sensitive and may produce a different
pattern for any energy it may radiate on adjacent channels.
Therefore, this fact suggests we should adopt a relatively
conservative field strength value for purposes of radio
astronomy site protection.
We propose to apply the same field strength limit to
low power TV stations, TV translators and TV boosters.
Since such stations operate with significantly smaller
facilities than full service UHF-TV stations, our proposed
approach would permit them much greater flexibility in
terms of location, while providing the radio astronomy
sites a level of protection equal to that provided by the
more powerful full service stations. Compliance with the
field strength restriction would be determined using the
standard prediction methods and the Commission's F(50,50)
propagation curves. Comments should address whether 72
dBu, 64 dBu or some other field strength value provides
adequate protection for the Channel 37 radio astronomy
operations and whether these values impose a significant
burden on TV use of these two channels. Parties that favor
a fixed separation distance as proposed by CORF should
identify the distance they believe is correct and support
CORF also indicates that it does not oppose the Commission's
"grandfathering" of existing stations and stations for
which a construction permit has been authorized on Channels
36 and 38. CORF requests that extension or reinstatement
of expired construction permits be conditioned upon using
a different channel.(n0) CORF urges the Commission to require
applicants for new stations on Channel 36 or 38 to amend
their applications to specify a different channel, if feasible.
We do not believe that action on CORF's proposed "grandfathering" provision is necessary. A review of Commission records indicates that only one full service TV station currently operates with facilities that produce a predicted field strength in excess of 64 dBu at any of the identified radio astronomy sites. WJWN-TV, Channel 38, San Sebastian, PR, is licensed at anERP of 85.1 kW and HAAT of 332 meters (m). At 90 degrees True, which is toward the Arecibo radio astronomy site, the WJWN-TV facilities are 85.1 kW at 232 m. With the distance between sites of 45.1 kilometers (km), the predicted field strength at the radio astronomy facility is 67 dBu. While no other station currently authorized on Channels 36 or 38 would exceed the proposed field strength of 64 dBu, there are three other full service stations that would be precluded from increasing to the maximum normally permitted facilities by adoption of the proposed protection standard.(n0)
In light of the preceding discussion, we believe that
a general grandfathering provision, covering any existing
or proposed facilities, is unnecessary. We propose to
consider the WJWN-TV situation discussed above as a waiver
of the proposed rule. WJWN-TV would not be permitted to
modify its facilities in such a way as to increase its
predicted field strength at the Arecibo radio astronomy
site. We propose that all other existingand future stations
would be required to comply with the proposed 64 dBu limit
when planning future facilities.
Additionally, we request comment on whether we should
also require applicants for new facilities (or those proposing
to modify existing facilities) on Channel 36 or Channel
38 that would be within 87.7 kilometers (55 miles) of a
listed radio astronomy site to notify CORF (or some other
appropriate radio astronomy representative) concerning
their proposed facilities. We believe that the proposed
rules, coupled with our application processing procedures,
are probably sufficient to ensure protection to radio astronomy
facilities. However, we ask whether notification procedures
similar to those contained in Section 73.1030 would serve
any useful purpose. Moreover, if such notification is
considered expedient, we ask for comment on the most appropriate
entity to notify. While the proposed rules do not contain
a notification requirement, we may adopt such a requirement
if the comments indicate that a significant benefit may
be afforded by such notification.
Finally, with respect to the allotment aspects of CORF's
petition, we propose to delete the Channel 38 allotment
currently specified for Hilo, Hawaii. We note that this
proposal appears to have only a very minimal impact on
the TV broadcast service because both channels 20 and 26
would remain available as vacant non-reserved channel allotments
in Hilo. Further, we propose to require that petitions
for rulemaking proposing Channel 36 or 38 allotments which
would be located within 87.7 kilometers (55 miles) of a
radio astronomy site, must demonstrate compliance with
the radio astronomy facility protection criteria adopted
as a result of this proceeding. The proposed rule changes
are indicated in Appendix A.
This is a non-restricted notice and comment rulemaking proceeding. Ex parte presentations are permitted, except during the Sunshine Agenda period, provided they are disclosed as provided in Commission rules. See generally 47 C.F.R. §§1.1202, 1.1203 and 1.1206(a).
Regulatory Flexibility Act
FEDERAL COMMUNICATIONS COMMISSION
William F. Caton
PART 73 - RADIO BROADCAST SERVICES
1. The authority citation for Part 73 would continue
to read as follows:
Authority: 47 U.S.C. 154, 303, 334.
2. Part 73 would be amended by revising Section 73.606(b)
so as to delete the reference to Channel 38 for Hilo, Hawaii,
§73.606 Table of allotments.
* * * *
(b) Table of Allotments.
* * * *
Hilo (Hawaii) 2, *4, 9, 11, 13, 14+, 20+, 26+, *32+
* * * *
3. Section 73.611 would be amended by revising paragraph
(a) to include a new subparagraph (5) as follows:
§73.611 Reference points and distance computations.
(a) * * *
(5) If the reference point for a proposed new allotment
on either Channel 36 or Channel 38 is within 87.7 kilometers
(55 miles) of a radio astronomy site specified in Section
73.613(b), the channel may be allotted to such community
based upon a showing that a station could be authorized
in conformance with Section 73.613.
* * * *
4. A new Section 73.613 would be added to Part 73 to
read as follows:
§73.613 Channel 37 radio astronomy protection.
(a) An application to construct a new TV station on Channel
36 or 38, or to change the facilities of an existing station
on Channel 36 or 38 will not be accepted if the field strength
of the proposed station would exceed 64 dBu at any of the
Channel 37 radio astronomy locations set forth in paragraph
(b) of this section. The field strength must be calculated
using the horizontally polarized visual effective radiated
power in the pertinent direction, the antenna height above
average terrain in the pertinent direction determined in
accordance with Section 73.684(d), and the F(50,50) curves
in Section 73.699, Figure 10b.
(b) Channel 37 is used for radio astronomy at the following locations:
Location N. Latitude W. Longitude
Owens Valley, CA 37°-13'-54" 118°-16'-34"
Mauna Kea, HI 19°-48'-16" 155°-27'-29"
North Liberty, IA 41°-46'-17" 91°-34'-27"
Hancock, NH 42°-56'-01" 71°-59'-12"
Los Alamos, NM 35°-46'-31" 106°-14'-44"
Pie Town, NM 34°-18'-04" 108°-07'-09"
Socorro, NM 34°-03'-43" 107°-37'-04"
Arecibo, PR 18°-20'-46" 66°-45'-11"
Fort Davis, TX 30°-38'-06" 103°-56'-41"
Saint Croix, VI 17°-45'-31" 64°-35'-03"
Brewster, WA 48°-07'-52" 119°-41'-00"
Green Bank, WV 38°-25'-59" 79°-25'-59"
PART 74 - EXPERIMENTAL, AUXILIARY, AND SPECIAL BROADCAST
AND OTHER PROGRAM DISTRIBUTIONAL SERVICES
5. The authority citation for Part 74 would continue
to read as follows:
Authority: Secs. 4, 303, 48 Stat. 1066, as amended, 1082,
as amended, 47 U.S.C. 154, 303, 554.
6. Part 74 would be amended by adding a new Section 74.711
to read as follows:
§74.711 Channel 37 radio astronomy protection.
An application to construct a new low power TV, TV translator or TV booster station on Channel 36 or 38, or to change the facilities of an existing station on Channel 36 or 38 will not be granted if the field strength of the proposed station would exceed 64 dBu at any of the radio astronomy locations set forth in Section 73.613(b). The field strength must be calculated in accordance with the procedure set forth in Section 73.613(a).
INITIAL REGULATORY FLEXIBILITY ANALYSIS
Reason for Action
Reporting, Recordkeeping, and Other Compliance Requirements
Federal Rules which Overlap, Duplicate, or Conflict with
the Proposed Rule
Description, Potential Impact and Number of Small Entities
Any Significant Alternatives Minimizing the Impact on Small
Entities and Consistent with the Stated Objectives
A P P E N D I X A 1. The authority citation for Part 73 would continue to read as follows: 2. Part 73 would be amended by revising Section 73.606(b) so as to delete the reference to Channel 38 for Hilo, Hawaii, as follows: 3. Section 73.611 would be amended by revising paragraph (a) to include a new subparagraph (5) as follows: 4. A new Section 73.613 would be added to Part 73 to read as follows: 5. The authority citation for Part 74 would continue to read as follows: 6. Part 74 would be amended by adding a new Section 74.711 to read as follows: A P P E N D I X B
Footnote 1 Report and Order, Docket No. 15022, 39 FCC 884 (1963).
Order, 53 FCC 2d 627 (1975) (Channel 37 reservation extended
through WARC-79); Second Report and Order, Gen. Docket
No. 80-739, 49 Fed. Reg. 2357 (January 19, 1984) (amending
Footnote US 246 to the U.S. Table of Frequency Allocations
domestically the WARC-79 reallocation of Channel 37 to the radio astronomy service); Order, Mimeo 4385 (released May 12, 1986) (amending §73.603(c) to reflect this reallocation).
Footnote 3 Because no stations of any type are authorized on Channel 37 the term "offending station" should be construed as a reference to stations operating on adjacent Channels 36 and 38.
Footnote 4 The Hilo allotment, at 39.3 kilometers (24.4 miles) from the Mauna Kea radio astronomy facility, is within the requested separation distance.
Footnote 5 All field strength calculations used in this Notice are derived using the Commission's F(50,50) propagation curves and refer to the field strength of the TV signal on the assigned frequency.
Footnote 0 CORF petition, p. 15.
KQCT (TV), on Channel 36 in Davenport, IA, is 87.1 km
(54.1 miles) from the North Liberty, IA radio astronomy
facility. It is currently licensed at a main lobe ERP
of 6.03 kW and an HAAT of 65 m. The proposed 64 dBu restriction
would limit any increase in future facilities to roughly
5,000 kW ERP at 340 m HAAT or 850 kW ERP at 610 m HAAT
in the direction of the radio astronomy facility.
WSBK-TV, on Channel 38 in Boston, MA, is 94.2 km (58.5 miles) from the Hancock, NH radio astronomy facility. It is currently licensed at an ERP of 2,340 kW and an HAAT of 354 m. The proposed 64 dBu restriction would limit any increase in future facilities to roughly 5,000 kW ERP at 425 m HAAT or 1600 kW ERP at 610 m HAAT in the direction of the radio astronomy facility.
WDWL (TV), on Channel 36 in Bayamon, PR, is 68.3 km (42.4 miles) from the Arecibo, PR radio astronomy facility. It is currently licensed at an ERP of 9.33 kW and an HAAT of 329 m. The proposed 64 dBu restriction would limit any increase in future facilities to roughly 650 kW ERP at 329 m HAAT in the direction of the radio astronomy facility.
Our review of the TV engineering data base also indicates that no low power TV, TV translator or TV booster station is authorized facilities or applying for facilities that would exceed a predicted field strength of 64 dBu at any of the radio astronomy sites. There is one low power TV station construction permit (K38DR in Cedar Rapids, IA) that is 29.1 km (18 miles) from the North Liberty, IA, radio astronomy facility. This station is currently authorized an ERP of 9.7 kW and its HAAT in the direction of North Liberty was determined to be 131 m using a Commission computer program and topographic data base. It thus appears to deliver a field strength of 63.9 dBu at the North Liberty radio astronomy site.